SAO PAULO 
Brazilians vote Sunday in national elections that could see front-running candidate Dilma Rousseff become the country's first female president, succeeding her popular ally and mentor.

Rousseff, a 62-year-old former guerrilla, represents the ruling Workers Party and is the hand-chosen successor of outgoing President Luiz Inacio Lula da Silva, who led Brazil to unparalleled economic growth and increasing political clout on the global stage.

The latest polls show her with a lead of about 20 percentage points over her closest rival, Jose Serra, a 68-year-old centrist from the Brazilian Social Democracy Party who was heavily defeated by Silva in the 2002 election.

The campaign has been short on substance and long on arguing about who would more efficiently continue the policies of the Silva presidency - eight years during which some 20.5 million people have been lifted from poverty.

Rousseff spent Saturday at Silva's side working crowds in the industrial city of Sao Bernardo do Campo, just outside Sao Paulo, Silva's hometown and a Workers Party stronghold. Trying to fight any complacency among her supporters, Rousseff downplayed her lead in the polls and testily deflected questions about where she might hold a victory party.

Instead, she spoke of economic advances under Silva, who is popularly referred to as Lula. Rousseff laid claim to his legacy, saying she was the candidate to transform Brazil into an economic power that leaves nobody behind.

"We are only going to do it with the path that President Lula has opened," Rousseff said. "I do not believe in a developed nation that has a part of its population marginalized. My goal is to continue President Lula's work at eradicating poverty."

Despite an ethics scandal that received heavy media coverage in the final weeks of the race, Rousseff's numbers barely ticked down and polls put her on the cusp of winning an outright majority Sunday and avoiding a runoff Oct. 31.

Nevertheless, Serra, who has struggled through a campaign that analysts said lacked focus and failed to resonate with many voters, expressed confidence that he would make it to a second round for another four weeks of campaigning during which voters could examine the candidates more closely.

"On Monday, it all begins again," he said while campaigning in Sao Paulo on Saturday. "We are going to a second-round vote for the good of the country."

If the election does go to a runoff, it could be due to spoiler candidate Marina Silva, a former environment minister who is not related to the president.

In recent weeks, the Green Party candidate's standing in the polls rose from a steady 10 percent throughout the campaign to about 14 percent in the wake of the ethics scandal.

Yet even if forced into a runoff, Rousseff is widely expected to become Brazil's next president.

"A second round would pit Dilma against Serra, but the difference between the two is too large to be breached in such a short period of time," said Amaury de Souza, a Rio de Janeiro-based political analyst. "Unless there is a new catastrophic disclosure regarding corruption or Dilma's health, she will win the second round."

About 135 million voters will also cast ballots for governors, mayors and state and federal houses of Congress.